Phonographic apparatus



Dec. 4, 1934. 1 T. rsAc|-rr| EBE|-1 y PHONOGRAPHIC APPARATUS Filed June l INVENTOR Al/@ENCE L5 Aff/72536 BY AlTTORNEY ble mirror about the axis o f vits Patented Dec. 4, 1934 PATENT OFFICE `rHoNoGRAPHIc APPARATUS Y Lawrence T. Sachtleben,

Radio Corporation of Delaware ij Oaklyn, N. J., assigner to America, a corporationy of Application .time 1, 192:3, seriaiNo. 673,863

7 Claims.

This invention relates to phonographic apparatus and more particularly to the variety thereof used forv recording sound upon a photographic film.

' It involves an improvement in sound recording apparatus wherein the light reecting mirror is actuated directlyby the diaphragm as disclosed in Fritts Patent 1,203,190 and relatesv more particularly to a number of improvements in the mirror actuating mechanism of such apparatus.

The particular apparatus herein described is especially adapted the operator thereof records his descriptive discussion while taking the picture.

Recording is accomplished by vibrating a narrow line of light transversely of a portion of the lm, andthis vibration of the line of lightis effected by the rotation or oscillation of a vibratasupport. One object of the invention is to effect the axial rotation of the mirror by means of manually controlled adjustment for the purpose o f obtaining a zero setting thereof.

. Another object of the invention is to provide means for retaining the mirror spindle in predetermined relation to the driving rod of the diaphragm Another object of the invention'is to provide means for prefocusing the optical system of the apparatus so thatthe recording units are interchangeable without further adjustment.

Another object of theinvention is to provide means for damping cantilever vibrations of the mirror carrying spindle.

Another object of the invention is to provide means for*y y'retaining the driving spindle and mirror spindle in cooperative relation, which will have substantially no eifect upon the frequency characteristics of the apparatus.

ln the drawing:

Fig. 1 is a rear view of a mirror driving mechanism made in accordance with my invention.

Fig. 2 is a sectional view along the middle of Fig. 1.

Fig. 3 is an enlarged view corresponding to the middle portion of Fig. 1.

Fig. 4 is an enlarged view sho-wing a modica tion of the driving rod and mirror spindle connections.

Fig. 5 shows the casing of the recording unit and the means for securing accurate adjustment thereof in relation to the film position.

Referring first to Figs. 1 and 2: A sound-box is provided enclosing the diaphragm 1, which 55 sound-box has a cover 2 tted with a mouthpiece for use in a camera wherein (Cl. 274-5)y 3, as well asarea'r cover 4. Through the rear cover 4 extends the driving rod 5 which is connected to the diaphragm 1 and vibrated longitudinally thereby. Pivoted against the driving rod 5 'is the mirror spindle 6, which is illustrated as a roddiamond-shaped in cross-section but may be of any other suitable form. Carried upon onevextremity of the rod 5 is the mirror '7 from which light is reiiected to the recording surface. y

The other of the acute angles of the diamondsliaped rod is pivoted against the supporting member 8 which forms axed pivot therefor.

`It will be apparent that sound waves Vimpingin'g upon the diaphragm will produce longitudinal movement of the rod 5 which will rotate or oscillate themirror spindle 6 about its pivot in the vsupporting member 8, and thereby cause shifting of the beam of lightwhi h is reflected from the mirror. The optical system for focussing the beam of light upon the mirror 'and converging it into the form of al narrow line upon the film, is no part of this invention and, so far as this invention is concerned, it is immaterial what form it may take although' the general arrangement shown in Taylor Patent 1,847,636 is quite satisfactory. Its construction and arrangement' will be readily understood by those skilled in the art. The member 8 is supported upon the member 9 which in turn is adjustably supported upon the rear face 4 ofthe sound-box.

The member 9 is, as shown, "of a T-shape with the ends of the cross-bar thereof fastened to the cover 4 by the screws 10. The middle of this portion is supported upon the case by the pin 11 which is set into the member 4 and upon which the member 9 can be moved. 'The screws 10 bend the member 9 very slightly over the member 11 upon which the member 9 is to be rotated by pressure applied at the extremity of the other leg thereof. This rotation is effected by'actuation of the screw 12 which is threaded into the member 4 and also into the member 9. As will be seen from Fig. 2, the portion of this screw which is threaded into the member 4 is of relatively large diameter while the portion threaded into the member 9 is of smaller diameter, and the pitches of the threads'thereon are in correspondence with these diameters. Due to the differential actionvth'erebetween, 'a very ne adjustment of the position of the member 9 can be secured, when' the member its held rigidly in such adjustment. l

It will be apparent that movement of the screw 12 will accomplish an appropriate movement of the member 8 andthereby effect rotatior'i of the spindle 6 which in turn adjusts the position of the mirror 7.

'Ihe member 8, which is provided with notches for pivoting the spindle 6, is secured to the member 9 by the screws 13 which holds it firmly against the pins 14 over which it is slightly flexed to prevent any independent vibration thereof. Since the pins 14 are located in the middle of the member 8 and the screws 13 are located at the ends thereof, the member 8 can be rotated on the pins 14 as a pivot for the purpose of securing proper alignment of the spindle 6, by loosening one of the screws 13 and tightening the other.,A

There may be some tendency for the spindle 6 to vibrate laterally. Any such vibration may be prevented in the manner shown in Fig. 3 wherein a small arm 15 is attached to the T-bar 9 and extends outwardly therefrompast the spindle 6. A small pad of rubber 16 is secured to the arm 15 and rests lightly against the spindle 6. This block of rubber serves to damp out any cantilever vibrations of the spindle 6 while at the same time it does not interfere with the freedom thereof to rotate.

Fig. 4 shows a slight modification of the construction shown in Fig. 2. In this figure the driving rod 5 is maintained firmly against the spindle 6, and this spindle is in turn maintained securely against the member 8, by the action of a spring 17. This spring 17 is secured to a pin 18 in the member 9 and the end of the spring extends over a spacing block 19 on the member 8. This end of the spring is attached to the member 5 in the groove 20 as shown.

It will be apparent that the spring 17 maintains the elements 5, 6 and 8 in proper relation to each other and, since the tension of the spring is transverse of the rod 5 and the material of the spring is quite flexible, it does not interfere with longitudinal vibrations of the member 5.

It will be apparent that other types of vibration-converting means other thanthe mirror 7 may be used if the construction is applied to other forms of apparatus, and the vibration-translating rod 6 may be of any cross-section functionally equivalent to the diamond-shape shown although the diamond-shape is apparently the most con- Venient form providing two opposite knife-edges for engagement with the other members.

Referring now to the adjusting means shown in Fig. 5, the drum upon which the film is carried past the recording point is indicated at 30. This drum is rotated upon a shaft 31 and coaxial with it is located a bushing 32 of predetermined diameter. 'I'his bushing is of annular form, and since the periphery thereof is co-axial with the shaft 31, it may be either merely slid over the said shaft and freely movable therewith, or may be fixed against rotation by attachment to the plate 35. However, since the friction of this bushing 32 with the pin 37 would tend to impede the rotation of the shaft 31, it is generally preferable to attach the bushing to the frame 35. The mirror vibrating mechanism described above is mounted at the right-hand end of the casing 33 as indicated and this casing 33 contains the exciter lamp` and the remainder of the optical system which is of such a nature as to be able to focus the required fine line of light upon a strip of film passing over the drum 30, this line of light passing out of the casing 33 through an aperture in the plate 34.

The casing 33 is secured to a portion of the camera or recorder frame 35 by means of the screw 36 or as many similar screws as may be necessary or desirable, and these screws pass through elongated holes in the casing 33 so that a slight movement of the member 33 toward or away from the sprocket 30 is permitted. In the casing 33 is drilled a hole of appropriate diameter into which is fitted a pin 37 which is secured in place by a screw 38. In manufacturing the device, the casing 33, when the optical system has been completely assembled, is placed in a jig and shifted until the optical system is in correct focus. The pin 37 is then extended until it contacts with a stop member in the jig and is secured firmly in place by tightening the screw 38. By this means the end surface of the pin 37 is maintained in uniform relation to the focal plane of the optical system.

If the bushing 32 is made of appropriate diameter, vthen when the unit 33 is inserted into the camera and brought to such a position that the pin 37 contacts with the bushing 32, the optical system will be accurately focussed upon a film upon the sprocket 30. f

It will be apparent that these recordingy units are not merely interchangeable with each other but can be exchanged between different recorders or cameras without refocussing.

The scope of this phase of the invention'l is not limited to directly actuated recording apparatus as, it will be apparent that a recording galvanometer or any equivalent apparatus which is provided with suitable members for abutment against and cooperation with the fixed members of the recording device may be substituted, and the camera or recorder can accordingly vbe used interchangeably for various purposes, according to which type of device is included therein.

Having thus described my invention, I claim:

1. Phonographic apparatus comprising a member arranged to be moved for translating sound impulses into light impulses, means comprising a pivotal support for said translation member, and means arranged to ex said means for shifting the position of the pivotal support.

2. Phonographic apparatus comprising a mirror spindle, means for oscillating the spindle, means includinga T-shaped member pivotally supporting said spindle, and means for flexing said member to adjust the position of said spindle.

3. Phonographic ymeans comprising a driving rod, a pivot member, a vibratable rod in pivotal engagement with said driving rod and with said pivot member and resilient means maintaining said driving rod, said yvibratable rod and said pivot member in engagement, the said resilient means acting laterally of the said driving rod.

4. Phonographic means comprising a driving rod, a pivot member, a vibratable rod in pivotal engagement with said driving rod and with said pivot member and resilient means maintaining said driving rod, said vibratable rod and said pivot member in engagement, the said resilient means acting laterally of the said driving rod, the said resilient means being freely yieldable in the direction of movement of the said driving rod.

5. Phonographic apparatus comprising a member arranged to be moved for translating sound impulses into light impulses, T-shaped means carrying a pivotal support for said translation member at the point of crossing thereof, and means arranged to torsionally ex the cross-bar of said means for shifting the position of the pivotal support.

6. Phonographic apparatus comprising a mirror spindle, means for oscillating the spindle,

engagement with said driving rod and with said pivot member and laterally flexible resilient means maintaining said driving rod, said vibratable rod and said pivot member in engagement, the said resilient means acting laterally of the said driving rod.

LAWRENCE T. SACHTLEBEN. 

